This is a renewal application for the operation of the core facilities of the Reproductive Endocrinology Center of the University of California, San Francisco. the core facilities include: (1) Assay Laboratory, (2) Molecular Biology Core, (3) Morphology Core, (4) Microcomputer Facility, (5) Primate Facility, (6) Analytical Separation Core, and (7) Administrative Core. The Reproductive Endocrinology Center is an integrated, interdepartmental research and training program at the University of California, San Francisco. It was established to study hormonal regulation of reproductive events at the subcellular, cellular, tissue and whole organism levels. A variety of species, including subhuman primates and humans, is being studied with the overall goal being to understand the physiologic and pathophysiologic regulation of the reproductive process in humans. More specifically, this is a multifaceted program with primary foci being studies of the hypothalamic-pituitary-gonadal-target tissue axis and the endocrine physiology of pregnancy. In addition to its longstanding foci on protein and steroid biochemistry, clinical investigation, and developmental and reproductive biology, there has been progressively increasing activity in the Center in the areas of reproductive neurosciences as well as cell and molecular biology. Currently, there are 16 faculty members on the staff of the Reproductive Endocrinology Center from the following Departments and Organized Research Units: Obstetrics, Gynecology and Reproductive Sciences, Anatomy, Physiology, Biochemistry and Biophysics, Pathology, Laboratory of Molecular Endocrinology and Cancer Research Institute. The existence of the core facilities has permitted the maximal development and use of frequently employed research procedures, has increased collaboration and interchange between the members of the Reproductive Endocrinology Center, has avoided unnecessary duplication, and thus has been, and continues to be, cost-effective.